PAS resins have high mechanical strength, high heat resistance, high chemical resistance, good formability, and good dimensional stability and, due to these characteristics, have been used as a material for components of electrical and electronic equipment, automobiles, or the like.
In many cases, such components are bonded to other components composed of an epoxy resin or the like in secondary processing. However, PAS resins have poor adhesiveness to other resins and, in particular, relatively poor adhesiveness to epoxy resins, which has posed a problem of poor adhesiveness between PAS resins and epoxy resins (hereinafter, this may be referred to simply as “adhesiveness”) that occurs, for example, when PAS resins are bonded to each other with an epoxy-based adhesive, when a PAS resin is bonded to another material with an epoxy-based adhesive, or when an electrical and electronic component is sealed with an epoxy resin.
On the other hand, since they have poor toughness, PAS resins are easily broken under a thermal cycle, that is, a cycle of cooling and heating, or a thermal shock. That is, PAS resins have low thermal shock resistance. In addition, reinforcement using a fibrous reinforcing material such as glass fiber results in occurrence of anisotropy, which causes warpage, torsion, or the like of the molded body. Thus, PAS resins do not have sufficiently good dimensional stability.
In light of such facts, several studies have been conducted for the purpose of improving the thermal shock resistance and dimensional stability of PAS resins and the adhesiveness of PAS resins to epoxy resins. For example, a PAS resin composition including glass fiber, an olefin polymer, an epoxy resin, and glass flake has been proposed (see PTL 1). However, the thermal shock resistance of the PAS resin produced by this method, in which a bisphenol A-type epoxy resin is used as an epoxy resin, is insufficient for practical use while the PAS resin has good adhesiveness to epoxy resins and good flowability.